We use QlikView to create a data mart and recently we had an issue where one of them associated tables stopped working and in the QlikView Table view the Preview for it became disabled. The resolution to recreate the application with the exact same script.
What is the cause of the Preview becoming disabled and the association not working when the associative fields seem correct
I wonder what caused it to have zero rows. I create a qlik data mart with must_include qvs script and deleting the qvw app and recreating it with a copy and reloading it so it had the same exact data model again fixed the issue. as if the QVW application become either corrupt or some setting changed.
For example the new application may have different interpretation-variables, is now with a different release created, has different settings especially in regard to section access and any possible data-reduction, the used script isn't identically respectively identically applied (a different load-order may change things), it's created from a different file-path ... probably some more possibilities ...
I think I would start with looking into the document-log to see if there are any differences between applications.